Begin implementing traits for a game record

sgf/src/game.rs

@@ -5,8 +5,7 @@ use crate::{
 use serde::{Deserialize, Serialize};
 use slab_tree::{NodeId, NodeMut, NodeRef, Tree};
 use std::{
-    collections::{HashSet, VecDeque},
+    collections::{HashMap, HashSet, VecDeque}, fmt::Debug, ops::Deref, time::Duration
-    time::Duration,
 };
 use uuid::Uuid;
 
@@ -56,6 +55,7 @@ pub struct Player {
 /// syntax issues, the result of the GameRecord is to have a fully-understood game. However, this
 /// doesn't (yet?) go quite to the level of apply the game type (i.e., this is Go, Chess, Yinsh, or
 /// whatever).
+#[derive(Clone, Debug, PartialEq)]
 pub struct GameRecord {
     pub game_type: GameType,
 
@@ -81,7 +81,7 @@ pub struct GameRecord {
     pub overtime: Option<String>,
     pub transcriber: Option<String>,
 
-    pub trees: Vec<Tree<GameNode>>,
+    pub trees: Vec<GameTree>,
 }
 
 impl GameRecord {
@@ -235,13 +235,13 @@ impl TryFrom<parser::Tree> for GameRecord {
 
         s.trees = tree.root.next.into_iter()
             .map(recursive_tree_to_slab_tree)
-            .collect::<Result<Vec<Tree<GameNode>>, GameError>>()?;
+            .collect::<Result<Vec<GameTree>, GameError>>()?;
 
         Ok(s)
     }
 }
 
-fn recursive_tree_to_slab_tree(node: parser::Node) -> Result<Tree<GameNode>, GameError> {
+fn recursive_tree_to_slab_tree(node: parser::Node) -> Result<GameTree, GameError> {
     let mut slab = Tree::new();
     let mut nodes: VecDeque<(NodeId, parser::Node)> = VecDeque::new();
 
@@ -269,7 +269,7 @@ fn recursive_tree_to_slab_tree(node: parser::Node) -> Result<Tree<GameNode>, Gam
         }
     }
 
-    Ok(slab)
+    Ok(GameTree(slab))
 }
 
 pub struct TreeIter<'a> {
@@ -298,6 +298,50 @@ impl<'a> Iterator for TreeIter<'a> {
     }
 }
 
+#[derive(PartialEq)]
+struct GameTree(Tree<GameNode>);
+
+impl Clone for GameTree {
+    fn clone(&self) -> Self {
+        match self.0.root() {
+            None => Self(Tree::new()),
+            Some(source_root_node) => {
+                let mut dest = Tree::new();
+                let dest_root_id = dest.set_root(source_root_node.data().clone());
+
+                // In order to add a node to the new tree, I need to know the ID of the parent in
+                // the source tree and the ID of the parent in the destination tree. So I want a
+                // lookup table that maps source IDs to destination IDs. But is that sufficient?
+                // Perhaps I can just keep a mapping from a source noderef to a destination ID.
+                // I don't think I can keep more than one mutable destination node.
+
+                let mut mapping: HashMap<NodeId, NodeId> = HashMap::new();
+                mapping.insert(source_root_node.node_id(), dest_root_id);
+
+                for source_node in source_root_node.traverse_level_order() {
+                }
+
+                Self(dest)
+            }
+        }
+    }
+}
+
+impl Debug for GameTree {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        self.write_formatted(f)
+    }
+}
+
+impl Deref for GameTree {
+    type Target = Tree<GameNode>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+
 pub struct MainlineIter<'a> {
     next: Option<NodeRef<'a, GameNode>>,
     tree: &'a Tree<GameNode>,
@@ -950,4 +994,14 @@ mod file_test {
             });
         });
     }
+
+    #[test]
+    fn it_can_copy_a_game_record() {
+        with_file(std::path::Path::new("test_data/multi-tree.sgf"), |games| {
+            let dest = games.clone();
+
+            assert_eq!(games.len(), dest.len());
+            assert_eq!(games[0], dest[0]);
+        });
+    }
 }